1. Field of the Invention
The invention relates to an arrangement for permitting the transmission of an electrical signal between areas of different pressure.
2. Background Art
A need arises in many applications for transmitting an electrical signal between areas of different pressure. In a tank that contains a fluid under pressure, for example, it is often necessary to conduct such a signal into the tank to control a solenoid-operated valve disposed inside the tank. Because the tank must be breached in order to pass a wire through to the valve, some provision must be made for maintaining a seal so as to prevent leakage of contents out of the tank, or to prevent contaminants from passing into the tank.
Various structures are known for establishing such a seal. U.S. Pat. No. 3,352,963, for instance, discloses a fitting including a high pressure side conductor rod and a low pressure side conductor rod that are joined together by a connector, which is received in an insulating sleeve. The sleeve and the connector are disposed within a pair of nested metal sleeves having complementary tapered sealing surfaces and seats. A hollow loading nut houses the sleeves and connector, and draws them together into sealing relation when the nut is threadably secured to a vessel wall. While this fitting is adequate for transmitting an electrical signal between areas of different pressure, the fitting is complex, bulky and costly to produce.
The invention addresses the shortcomings of the prior art by providing an arrangement for passing an electrical signal between areas of different pressure that is simple, compact and inexpensive.
Under the invention, an arrangement is provided for passing an electrical signal between a first area having a first pressure, and a second area having a second pressure, wherein the first pressure is normally greater than the second pressure. The arrangement includes a body disposable between the first and second areas. The body has a first surface disposable adjacent the first area, and an aperture extending from the first surface. A sleeve is non-threadingly engaged with the body and defines a passage. The sleeve further has a first portion disposed adjacent the first surface, and a second portion disposed in the aperture. The arrangement further includes an electrically conductive element disposed at least partially in the passage. When the sleeve is exposed to the first pressure, the first portion is urged toward the first surface of the body.
The arrangement further preferably comprises a first conductive member in electrical communication with the conductive element and adapted to extend into the first area, and a second conductive member in electrical communication with the conductive element and adapted to extend into the second area.
The passage of the sleeve may include a main channel and a first conductive element channel extending from the main channel. With such a configuration, the conductive element is disposed at least partially in the first conductive element channel.
The arrangement may also include a second conductive element channel extending from the main channel, and an additional conductive element disposed at least partially in the second conductive element channel. preferably, but not necessarily, the first and second conductive element channels are canted with respect to a sleeve axis of the sleeve. With such a configuration, the size of the sleeve can be minimized, while still providing sufficient space for other components installed in the sleeve.
The conductive element may be a terminal having a radially extending projection and first and second shank sections extending from the projection. The arrangement may also include an insulator disposed between the terminal and the sleeve. While the insulator may have any suitable configuration, the insulator preferably has a main portion and first and second annular portions extending from the main portion. The first annular portion extends between the projection and the sleeve, and the main portion and the second annular portion extend between the second shank section and the sleeve.
Under another embodiment of the invention, an arrangement for passing an electrical signal between first and second areas includes a body disposable between the first and second areas and having an aperture. A sleeve is disposed at least partially in the aperture. The sleeve includes a sleeve axis, a main channel and first and second terminal channels extending from the main channel and canted with respect to the sleeve axis. A first terminal is disposed at least partially in the first terminal channel, and a second terminal is disposed at least partially in the second terminal channel.
These and other objects, features and advantages of the invention are readily apparent from the following detailed description of the best modes for carrying out the invention, when taken in conjunction with the accompanying drawings.